The present invention relates to a program update apparatus and a program update method. In particular, the present invention concerns a program update apparatus and an update method thereof, which is used for a bug fixing process and a version-up process of an apparatus built-in system.
In programs of a system such as an apparatus built-in system, a bug fixing process for eliminating bugs and a version-up process for improving a program and for updating data are sometimes required. For this reason, in a conventional system, a program re-writing process in an apparatus built-in system, etc. is sometimes carried out.
FIG. 1, for example, shows a case of a home-use consumption measuring device for measuring energy consumption. The energy consumption measuring device 1 is placed on an outer wall or the like of a house, and energy is supplied to apparatuses 3 for use in the home 2 through a first energy supply line 4, a second energy supply line 5, etc. via the consumption measuring device 1. For example, energy, supplied through the first energy supply line 4, is electricity, and the consumption measuring device 1 measures and calculates the consumption of electricity. Moreover, energy, supplied through the second energy supply line 5, is gas, and the consumption measuring device 1 measures and calculates the consumption of gas.
The objective of such a consumption measuring device is to measure the consumption of energy such as electricity and gas, and these data are used for purposes other than collection of rates. For example, when a detailed consumption trend on an hour basis for a day or a week is obtained, based on the data, the energy supplier can set a detailed charge system on an hour basis for each of the energy consumers, thereby making it possible to improve the service. Moreover, by setting a higher energy consumption charge during a time zone corresponding to a consumption peak, it becomes possible to reduce the gross consumption of energy, and consequently to prevent an energy supply shortage due to concentration of energy consumption onto a specific time zone.
In order to carry out the collection of rates and to effectively use the data as described above, the energy supplier needs to read a meter of a consumption measuring device in each home to check the energy consumption. For this reason, a measurer (inspector), dispatched from a control center (an energy supplier such as an electric company or a gas company) visits each home to read the meter of each consumption measuring device. However, in such a meter reading method for the consumption measuring device in each home using handwork, the number of homes on which meter-reading operations can be conducted per day is limited, and personnel expenses become higher, resulting in low efficiency.
For this reason, a system has been proposed in which the meter-reading operations are automatically carried out on consumption measuring devices placed in respective homes from a remote place. In such a prior-art system, as shown in FIG. 2, a data-collecting device 9 is placed on an electric pole 8 or the like, and the consumption measuring device 1 of each home 2 is connected to the control center 6 through the data collecting device 9. The data collecting device 9 is a device having such a function that data is collected from the consumption measuring device 1 of each home on 2 a fixed time basis to send the resulting data the control center 6. The data collecting device 9 is attached to an inaccessible place for people such as an electric pole 8 because of availability of a power-supply, less interrupting objects in terms of electric waves, and prevention of human touch. The data collecting device 9 is normally connected to the consumption measuring device 1 of each home 2 as well as to the control center 6 through communication lines 10, 11, etc.
Such a system makes it possible to automatically inspect consumption measuring devices of many homes from a remote place (control center 6), to cut personnel expenses, and consequently to eliminate the limit of the number of meter-reading operations per day; thus, it becomes possible to carry out the meter-reading operations efficiently.
Moreover, the following description will exemplify another case in which a device installed in a house is operated from outside. In an example shown in FIG. 3, devices 12A, 12B, installed in a home 2 are connected to a device control unit 14 through signal lines 13, and the respective devices 12A, 12B are operated outside the home 2 through the device control unit 14 connected to a communication line 15 such as a telephone line and a network outside the home 2, or information from the devices 12A, 12B is obtained from outside. For example, in the case when the device 12A is a monitor camera, the image of the monitor camera is monitored from outside by using a mobile computer connected to a telephone line or a mobile telephone, or the image-pickup direction of the monitor camera can be operated, and in the case when the device 12B is a video recorder, a recording reservation of the video recorder can be carried out from outside. In the case when a device 12C is a monitoring sensor required for home security, information from the security system can be obtained outside the home even from a remote place.
Various devices are proposed as such devices connected to the device control unit 14, and pieces of information are different depending on the respective devices, with the result that the system program of the device control unit 14 needs to be rewritten for each of the devices.
Moreover, in the case when those devices are used in a system related to home security, the device control unit 14 should be maintained without freezing during a home security operation. Freezing refers to a state in which no response is received from the device causing incapability of informing the state externally or incapability of receiving inputs from outside. The home security refers to a system for detecting an invasion of any dubious character, a fire, a gas leak, any emergency information, or any emergency or rescue situation, and when any freeze occurs in the device control unit 14, the home security system no longer functions, causing degradation in the reliability of the device control unit 14.
The following description will discuss technical problems with the device built-in system externally connected through communication lines, for example, devices such as the above-mentioned data collector and device control unit.
In the data collector 9 and the device control unit 14, a bug is sometimes found in the system (operation program), and in such a case, any bug fixing operation is required in the system program. Moreover, when any new device (for example, a consumption measuring device 1) is added and connected to the data collector 9 and the device control unit 14, the corresponding functions need to be added to the respective system programs, or the respective system programs need to be updated (renewed). Here, in order to upgrade the programs for bug fixing or addition of new functions., the program of the built-in system inside the data collector 9 and the device control unit 14 need to be re-written.
In the case when such a program re-writing process is required, for example, if an updating program is supplied to the user so as to have the user rewrite the program, it is not possible to expect the user to properly rewrite the program or to carry out a recovering process of a frozen program, in the case when he or she is poor at mechanics. Moreover, in most cases, individual data collectors 9 and device control units 14 are located at remote places from the program supplier (managing center, etc.), and the data collectors 9 and the device control units 14 also tend to be placed at inaccessible places (on electric posts, etc.). Therefore, when the rewriting process of the system program is required, it is necessary to automatically carry out a rewriting process through communication lines, etc. without the necessity of handwork.
Moreover, in the case of device control unit 14, etc. related to home security, it is not possible to stop the system for the rewriting process, and it is necessary to carry out the rewriting process while the system is being operated; therefore, even in the case when the system is frozen during the rewriting process, it is necessary to reactivate the system as a temporary measure and to operate the system.
Therefore, depending on device built-in systems, there have been demands for an updating method in which a program rewriting process is automatically carried out through communication lines, etc. and the system is free from freezing even in the event of an emergency situation.
Even in an conventional system, a program rewriting process of a device built-in system is carried out through a communication line. However, this process is carried out on the premise that a program is operated correctly, and only a check is made as to whether or not the rewriting process has been done correctly. For this reason, no rewriting process is carried out on an essential portion. Further, in the case when only the checksum is utilized for checking the program, in the event of a plurality of errors, the value to be checked might coincide with a correct value, resulting in a possibility of erroneous recognition of a correct rewriting operation.
Moreover, in the conventional rewriting system, it is not possible to properly deal with a program having any bug, and complicated processes such as network downloads cannot be carried out unless the operation system is operated.